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Biomedical subjects

D G Hardy

Publications and source records attributed to D G Hardy.

At least 73 records · Page 4Linked to original sources

Thoracic outlet syndrome.

Thoracic outlet syndrome can usefully be regarded as a peripheral entrapment syndrome. Disease processes or anatomical anomalies at the thoracic outlet may in suitable circumstances give rise to compression of neurological or vascular structures traversing the outlet. Investigation involves careful radiological and electrical assessment. Myelography is usually necessary and angiography may be required. Ninety per cent of patients present with neurological complaints and these can normally be managed conservatively. In the 10 per cent of patients who have vascular involvement urgent investigation and early surgery may be necessary if ischaemic complications are to be avoided.

Adult↗

Bombs for kicks.

Explore the source record for details and available documents.

Accidents↗

Microsurgical anatomy of the superior cerebellar artery.

Fifty cerebellar hemispheres from 25 adult cadavers were examined. The superior cerebellar artery (SCA) was present in each of the 50 hemispheres. Forty-three SCAs arose as a single trunk, and 7 arose as duplicate trunks. One solitary trunk and the rostral trunk of one duplicate vessel arose from the posterior cerebral artery. The remainder arose from the basilar artery. The SCA was divided into four segments: the anterior pontomesencephalic segment lay below the oculomotor nerve; the lateral pontomesencephalic segment course; below the trochlear and above the trigeminal nerve; the cerebellomesencephalic segment coursed in the groove between the cerebellum and the upper brain stem; and the cortical segment was distributed to the cerebellar surface. The SCAs arising as a single trunk bifurcated into a rostral and a caudal trunk, corresponding to the runks formed by a duplicate origin. The rostral trunk supplied the medial and the caudal trunk supplied the lateral parts of the cerebellar cortex. The SCA gave off perforating, precerebellar, and cortical arteries. The perforating arteries penetrated the interpeduncular fossa, the cerebral peduncles, the junctions of the superior and middle cerebellar peduncles, and the colliculi. The precerebellar branches arose within the cerebellomesencephalic groove and supplied the adjoining parts of the cerebellum and brain stem. The cortical branches were divided into vermian, hemispheric, and marginal arteries. The 50 SACs had points of contact with 32 oculomotor, 46 trochlear, and 26 trigeminal nerves. (Neurosurgery, 6: 10--28, 1980)

Arteries↗

Microsurgical anatomy and dissection of the sphenoid bone, cavernous sinus and sellar region.

The topographic and internal anatomy of the sphenoid bone is reviewed with an emphasis on the relationships important to the transcranial and subcranial surgical approaches to the sphenoid sinus, sella turcica and cavernous sinus. A stepwise method of study and dissection is outlined. The equipment and materials needed for sphenoid bone dissection in the laboratory are reviewed.

Cavernous Sinus↗

Recurrence of medulloblastoma after homogeneous field radiotherapy. Report of three cases.

Three cases are reported of posterior fossa medulloblastoma in children. In each case metastatic spread occurred despite homogeneous field radiotherapy to the whole neuraxis; the secondary tumor was located in the subfrontal region. In the two cases in which operative removal of the metastasis was carried out, the tumor was found to be extracerebral and was attached to the dura in the region of the cribiform plate. The "face-down" position of patients during operations on the posterior fossa makes this area the most dependent part and therefore the most likely recipient of tumor cells shed at operation. This area has not previously been included in the field of maximum dosage for radiotherapy, but as a result of these findings a modification in technique of radiotherapy has been suggested.

Brain Neoplasms↗

Microsurgical relationships of the superior cerebellar artery and the trigeminal nerve.

Comparison and distortion of the trigeminal nerve by a tortuous and elongated superior cerebellar artery (SCA) is postulated to be a frequent cause of trigeminal neuralgia. This theory and the use of operative therapy in which the offending arterial loop is separated from the trigeminal nerve has created a need for more detailed information on the relationship of the SCA and the trigeminal nerve. In order to meet this need, 50 trigeminal nerves and the adjacent SCA were examined in 25 adult cadavers. Twenty-six of the 50 nerves examined had a point of contact with the SCA, but it was uncommon for the arterial contact to produce distortion of the nerve. In six instances, the contact was at the pontine entry zone of the trigeminal nerve, the site of arterial compression postulated to be associated with trigeminal neuralgia. Four trigeminal nerves (8%) had a point of contact with the anterior inferior cerebellar artery (AICA). The fact that large arteries are commonly in contact with the trigeminal nerve is important not only because of the controversial relationship of neurovascular contact to trigeminal neuralgia, but because of the possibility that major vessels may be encountered and injured during rhizotomy and other posterior fossa operations on the trigeminal nerve.

Adult↗

The effect of RMI 12, 936 synthetic antiprogestional steroid, on ovarian steroidogenesis in the rat.

A series of physiochemical investigations confirmed that the product of chemical and enzymatic isomerization of RMI 12,936 was 7alpha-methyltestosterone. The total activity per pair of ovaries of delta5 3-ketosteroid isomerase in vitro was unchanges by RMI 12,936 pretreatment or by advancing pregnancy, significant changes in ovarian weight being accompanied by reciprocal changes in enzyme activity/mg tissue. The initial rate of isomerization of RMI 12,936 was approximately five times greater than the corresponding rate of delta5-progesterone isomerization at equal substrate concentrations. It is concluded that RMI 12,936 does not inhibit progesterone biosynthesis by alteration of delta5 3-ketosteroid isomerase activity, but that it may do so by acting as an alternative substrate for this enzyme.

Androstenols↗

Hypertension and renal artery stenosis with aneurysm formation in a solitary kidney in a patient with neurofibromatosis.

A case of hypertension in a patient with neurofibromatosis and renal artery stenosis with aneurysm formation in a solitary kidney is described. Studies of plasma renin activity and body sodium content are presented and have been related to findings in patients and experimental animals with renovascular hypertension. A reconstructive operative procedure is described in which the kidney is perfused in situ.

Adult↗